.student-learning {
    font-family: 'Roboto', sans-serif;
    background: linear-gradient(135deg, #e0eafc, #cfdef3);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    color: #333;
}

/* 页头 */
.header {
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: #fff;
    padding: 25px 20px;
    text-align: center;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

.header-inner {
    max-width: 800px;
    margin: 0 auto;
}

.header h1 {
    margin: 0;
    font-size: 2.6em;
}

.card-counter {
    margin-top: 10px;
    font-size: 1.2em;
}

.last-feedback {
    margin-top: 8px;
    font-size: 1em;
}

.highlight {
    font-weight: bold;
    color: #ffeb3b;
}

/* 主体区域布局 */
.main-content {
    flex: 1;
    display: flex;
    align-items: flex-start;
    justify-content: center;
    padding: 30px;
    gap: 20px;
}

/* 左右侧边栏 */
.sidebar {
    background: #fff;
    border-radius: 16px;
    padding: 20px;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
}

.left-sidebar {
    flex: 1;
    max-width: 200px;
}

.right-sidebar {
    flex: 1;
    max-width: 200px;
}

.sidebar h2 {
    margin-top: 0;
    font-size: 1.5em;
    border-bottom: 2px solid #667eea;
    padding-bottom: 8px;
    margin-bottom: 15px;
}

.sidebar ul {
    list-style: none;
    padding: 0;
    font-size: 1em;
    line-height: 1.6;
}

.tip {
    font-size: 1em;
    line-height: 1.6;
    margin-bottom: 15px;
    color: #555;
}

.tip-button {
    padding: 8px 15px;
    font-size: 0.9em;
    background: linear-gradient(135deg, #667eea, #764ba2);
    color: #fff;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.tip-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

/* 中间卡片区域 */
.card-area {
    flex: 2;
    max-width: 600px;
}

.card-container,
.summary {
    background: #fff;
    border-radius: 16px;
    padding: 30px;
    width: 100%;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
    text-align: center;
    position: relative;
}

.card {
    animation: cardIn 0.6s ease-out;
}

@keyframes cardIn {
    from {
        transform: translateY(20px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.card-title {
    margin-top: 0;
    font-size: 2em;
    color: #444;
}

.text {
    font-size: 1.3em;
    margin: 15px 0;
    color: #555;
}

.pinyin,
.translation,
.difficulty {
    font-size: 1em;
    margin: 8px 0;
    color: #777;
}

.definition {
    font-size: 1em;
    margin: 12px 0;
    color: #666;
    background: #f9f9f9;
    border-left: 4px solid #667eea;
    padding: 8px 12px;
    border-radius: 4px;
}

.quote {
    font-size: 1.1em;
    margin: 12px 0;
    color: #555;
    font-style: italic;
    animation: bounce 1s;
}

@keyframes bounce {
    0% {
        transform: scale(0.95);
    }

    50% {
        transform: scale(1.05);
    }

    100% {
        transform: scale(1);
    }
}

.quote-author {
    display: block;
    margin-top: 4px;
    font-size: 0.9em;
    color: #888;
}

.actions {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: center;
    margin-top: 20px;
}

.action-button {
    flex: 1 1 30%;
    padding: 12px 8px;
    font-size: 1em;
    border: none;
    border-radius: 8px;
    background: linear-gradient(135deg, #ff758c, #ff7eb3);
    color: #fff;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    min-width: 80px;
}

.action-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.progress-bar {
    background: #eee;
    border-radius: 8px;
    margin-top: 20px;
    height: 10px;
    width: 100%;
    overflow: hidden;
}

.progress {
    height: 100%;
    background: linear-gradient(135deg, #667eea, #764ba2);
    width: 0;
    transition: width 0.5s ease;
}

.summary h2 {
    font-size: 2em;
    margin-bottom: 15px;
}

.summary ul {
    list-style: none;
    padding: 0;
    text-align: left;
    margin: 20px 0;
}

.summary li {
    margin-bottom: 10px;
    font-size: 1em;
}

.restart-button {
    padding: 12px 25px;
    font-size: 1.1em;
    background: linear-gradient(135deg, #43e97b, #38f9d7);
    color: #fff;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.restart-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

/* 渐隐渐显动画 */
.card-slide-enter-active,
.card-slide-leave-active {
    transition: all 0.6s ease;
}

.card-slide-enter,
.card-slide-leave-to {
    opacity: 0;
    transform: translateY(20px);
}